#include <iostream>

double light(double);

int main()
{
	using namespace std;

	cout << "Enter the number of light years: ";
	double lightNum;
	cin >> lightNum;

	cout << lightNum << " light years = " << light(lightNum) 
		<< " astronomical units." << endl;
	
	return 0;
}

double light(double num)
{
	return num * 63240;
}
